Safety lock for treadle operated hammers



July 7, 1959 P. A. ETTER SAFETY LOCK FOR TREADLE OPERATEDHAMMERS Filed Jun e 4, 1956' 2 Sheets-Sheet l INVENTOR. PAUL A. ETTER DECEASED qaqmas x I 6?- AJ. 4! 9060/ m ATTORNEYS July 7, 1959 P. A. ETTERY 2,893,263

' SAFETY LOCK FOR TREADLE OPERATED HAMMERS Filed June 4, 1956 2' Sheets-Sheet 2 I Fig. 4 I I IN V EN TOR. PAUI A. ETTER ATTQRNEYS United States Patent SAFETY LOCK'F OR TREADLE OPERATED HAMMERS Paul A. Etter, deceased, late of Wood-Lynne, N.J., by Dorothy E. Dyl, administratrix, Wood-Lynne, NJ.

Application June 4, 1956, Serial No. 589,349

1 Claim. (Cl. 74-566) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to a treadle operated device such as a forging hammer, and has for an object to provide a safety lock which must be moved in a direction different from that in which an operators foot is moved for actuating said treadle in order to unlock the treadle for movement of the hammer.

A hand was mashed by the usual hammer actuating treadle having been accidentally pressed down prematurely, causing a hammer blow with disastrous results. One prior art suggestion for an accident preventing safety device was a foot guard that was automatically moved transversely of a pedal to push an operators foot off the pedal and prevent the hammer from operating too long. This device did not lock the hammer against the first blow being struck prematurely. Another suggestion was a hand operated safety device but an objection to it was the fact that it did not allow a workman to use both hands upon the work and instead required one hand to be withdrawn for control of the safety device.

According to this invention, a safety stop is provided for preventing actuation of the treadle and such stop is moved by an operators foot in a dififerent direction from that in which the foot moves to actuate the treadle. This different foot movement leaves both hands of the operator free to hold the work and moves a stop or abutment out of the path of movement of the treadle before a first blow can be struck with the hammer.

Referring to the drawings:

Fig. 1 is a bottom view of the device of Fig. 2.

Fig. 2 is a top plane view of a preferred embodiment of this invention.

Fig. 3 is a perspective of the left end of the device shown in Fig. 2.

Fig. 4 shows the treadle locking mechanism in combination with a hammer actuated by the treadle.

Fig. 5 shows a top plane view of a modified construction embodying this invention.

To prevent premature pressing of the treadle '10 a stop or abutment 11 is placed under the treadle for this purpose. This stop is shown in Fig. 3 as being mounted on a lever pivoted at 12 to a stationary base member 13. An operators foot is located as shown at 14 in Fig. 3 with the toe portion resting against the projection 15. By applying a counterclockwise movement to the projection 15 as shown in Figs. 2 and 3 the lever rotates about its pivot and the stop or abutment 11 moves out from under the treadle enabling the treadle to be pressed down for operating the hammer. A spring 16 has one end secured to the stationary member 13 and its other end secured to the lever so that as the lever is swung with the post moving in a counterclockwise direction, then upon release of the operators foot from the pro- 11 to a position in which the stop 11 is under the treadle 2,893,263 Patented July 7, 1959 To enable an operators foot 21 to be in another position and still operate the treadle release mechanism the lever 18 is pivoted at 19 to the stationary member 13 and a rod 17 pivotally connects the two levers as shown in Fig. 2. Movement of the post or projection 20 in the same counterclockwise direction in Fig. 2 causes the stop 11 to be moved out from under the treadle 10 and in either case the spring 16 returns each lever to its original position with the stop under the treadle 10.

In Fig. 4 the treaclie 10 and its stop 11 on the lever shown are illustrated as being connected to a power hammer 22 located above an anvil or other work support 23 for actuation of the hammer by the treadle 10 in the usual manner.

In Fig. 5 the treadle 10a has a stop 11a located under it and to remove the stop from beneath the treadle a lever 24 is pivoted at 25 the lever being provided with one or more toe recess portions 26 so that upon movement of an operators foot radially inward the lever 24 is caused to move about its pivot 25. Upon release of the operators foot, or its withdrawal radially outward, spring 27 causes a return of a lever 24 to its original position, which is illustrated with the stop 11a beneath the treadle 10a, to prevent its accidental operation.

Two advantages distinguish this invention from the prior art. One is the prevention of accidental initial operation of the forging hammer 22. Another is the fact that an operators hands are left free to manipulate the work upon the mandrel 23 and the operators hands are not required to adjust any stop mechanism or safety lock for the treadle inasmuch as that is accomplished by the operators foot.

I claim:

In a power hammer having a treadle for controlling the same, said power hammer having a stationary base member, the combination therewith of the improvement whereby said treadle may be controlled by an operator in different angularly spaced positions and whereby said treadle may be locked against control of said power hammer when an operator is in any one of said different positions, said improvement including said treadle extending circularly around said power hammer stationary base member at least far enough to be controlled by an operator when in any one of said spaced positions, a stop carried by said base for holding the treadle against control movement thereof, said stop being swingable to a treadle unlocking position in which control movement of the treadle may occur, said treadle unlocking movement of said stop being in response to movement of an operators foot in a diiferent direction from that in which an operators foot moves in controlling said treadle for starting said power hammer, said unlocking movement being independent from the operation of the power hammer, a lever pivoted at one end to said stationary base member, said stationary base member being placed along side of the treadle, a spring adjacent the opposite end of said lever for cooperation with said stationary base member and lever, said lever having a plurality of spaced apart toe recess portions along one side thereof, said stop being attached to the other side of said lever, whereby upon movemcnt of an operators foot radially inward at one of said toe recess portions said stop moves out of the path of said treadle, and withdrawal of the operators foot radially outward causes the spring to return the lever to its original position with said stop beneath the treadle in the locking position.

Grandy Jan. 7, 1919 Piaser Apr. 26, 1921 

